Tokyo stocks opened lower Wednesday as semiconductor-related issues tracked U.S. tech falls overnight and caution grew over a possible interest rate hike by the Bank of Japan before it concludes a policy meeting later in the day. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average fell 536.14 points, or 1.39 percent, from Tuesday to 37,989.81. The broader Topix index was down 33.61 points, or 1.22 percent, at 2,720.84. On the top-tier Prime Market, decliners included electric appliance, transportation equipment and real estate issues. The U.S. dollar plunged by around 2 yen …